Apparatus for heat setting synthetic fibre yarns



Ail-Q 1968 NOBUHISA KODAIRA ETAL 3,395,433

APPARATUS FOR HEAT SETTING SYNTHETIC FIBRE YARNS Filed July 10, 1967 H0810 M0 T561 m/ms/vTaR: .0)

are) a United States Patent 3,395,433 APPARATUS FOR HEAT SETTING SYNTHETIC FIBRE YARNS N obuhisa Kodaira, 851 Kamirenjyaku, Mitaka-shi, Tokyo, Japan, and Norio Motegi, 1-28 Sakura, Setagaya-ku, Tokyo, Japan Filed July 10, 1967, Ser. No. 652,304 Claims priority, application Japan, July 18, 1966, 41/ 46,538 7 Claims. (Cl. 28-62) ABSTRACT OF THE DISCLOSURE This invention comprises a vertical passage through which a crimped synthetic fibre yarn to be heat treated is passed.

Heat is applied to the wall of the passage by means of a liquid in a closed vertical container adjacent the passage wall. Liquid in the container is heated by a heating element to vaporize it. The vapor fills the space of the container, thereby heating the wall of the passage and the fibre yarn therein. An exit pipe at the top of the container conducts the vapor out of the top into a condensing chamber. The chamber contains a baflle divider open at the bottom, which results in separation of the purer phase of the condensate on one side of the baflle. A standpipe in the chamber on one side of the bafile removes the purer phase which is recycled to the bottom of the container.

This invention relates to improvements in vapor heating apparatus for heat setting crimped synthetic fibre yarns.

The apparatus comprises a vertical type of closed vessel adapted to contain a heat medium liquid and its vapor. The outside wall of the vessel is grooved to provide a channel through which yarn after being crimped by a crimping device is continuously fed so as to heat set. In the bottom part of the vessel, an appropriate volume of heat medium liquid and a heater is disposed.

The heat medium liquid is heated by the heater to produce vapor which fills the space in the vessel above the liquid.

Under the normal conditions, the Vessel is to be heated uniformly over its full length. However when the apparatus is operated for a long time, vapor produced from low boiling liquids which is contained in trace amounts in the heat medium liquid results in uneven temperature distribution in the upper and lower parts of the vessel. Also when a length of yarn runs through the channel at theside of the vessel, oily substances attached to the yarn dries by the heat transferred thereto and it eventually carbonizes.

The purpose of the present invention is to automatically drive out such gases and low boiling point material, although they be in trace amounts, which are inevitably mixed in Dowtherm E used as a preferred liquid in the apparatus.

Another object of the present invention is to protect yarn from being blurred and to avoid the reduction of heat transfer efficiency to yarn which will be caused by carbonized substances deposited on the inner surface of the channel through which the yarn passes.

Another object of the present invention is to attain better crimping of yarn by heat setting it with increased heat transfer efficiency.

The apparatus of the present invention comprises a plurality of longitudinal closed vessels, the bottom part of each vessel being communicated with the others by lower tubes. Above and outside the vessels there is pro- 3,395,433 Patented Aug. 6, 1968 ice vided a separating vessel for separating heat medium liquid, the upper portion of which is communicated to the upper portion of each closed vessel through a vapor tube. The bottom portion of the separating vessel is communicated through return standpipes to said lower tubes. One side of each closed vessel is grooved to provide narrow channels for passing yarn. A heat element extends through the bottom portion of each vessel and the lower tubes where a heat medium liquid is disposed in an amount to submerse the heat element. In said separating vessel a baffie is provided in a location between the outlet of said vapor discharging pipe and the inlet of said standpipes. A space is provided between the lower end of said baflie and the bottom of the separating vessel. The inlet of the standpipe is positioned at a higher level than the lower end of said bafile. The separating vessel is housed in a heat exchanger, the inlet of which is communicated through a pipe to the upper part of the channel provided on the side wall of each closed vessel. The outlet of the heat exchanger is communicated through a pipe to the lower part of said channel.

The invention is more particularly described with reference to the accompanying drawings, in which:

.FIG. 1 shows schematically a front elevational view of a first embodiment of apparatus of the invention.

FIG. 2 is a cross section taken along the line 11-11 of FIG. 1.

FIG. 3 is a cross section taken along the line III of FIG. 1.

FIG. 4 is a cross section of a second embodiment, corresponding to the section shown in FIG. 2.

FIG. 5 is a cross section taken along the line VV of FIG. 4.

FIG. 6 is a cross section of a third embodiment, corresponding to the section shown in FIG. 2.

FIG. 7 is a cross section taken along the line VII-VII in FIG. 6.

FIG. 8 is a piping system of the apparatus shown in FIG. 4 and FIG. 6, partly broken away.

In drawings, the apparatus, generally, comprises a plurality of vertical closed vessels 1.

The outer surface of the vessels is grooved to provide a desired number of channels 2. A length of yarn 2 is to be passed through each channel. Each vessel comprises an upper vapor chamber 3 contiguous with a lower portion which contains a liquid. A jacket 4 is provided on the outside of each vessel 1. The bottom of the vessels 1 are communicated with each other by lower tubes 5. A heater 6 is provided in the lower tubes extending through the bottom of the vessels 1 wherein a heat medium liquid 7 is disposed in an amount to submerge the heater.

Heater 6 is preferably electrical and vapor from the liquid 7 fills the vapor chamber 3 thereby yarn passing through the channel 2 is heated. Thus the yarn is heat set in its crimped state.

The upper part of each vessel 1 is communicated by upper tubes 8 to a laterally extendin separating vessel 9 in which is provided a bafile wall 10 to delineate two portions 9 and 9" respectively. Between the lower end of this bafiie wall 10 and the bottom of the separating vessel, there is provided a space 10. At the upper part of one of the portions 9 in said separating chamber, one end of an upper tube 8 is open and the lower part of the other portion 9" is communicated to the top end of a return standpipe 11. The top end of said standpipe is positioned above the lower end of said baffle 10. The lower end of pipe 11 is communicated to the lower tube 5.

Vapor chamber 3 in closed vessel 1 is communicated with a bellows 12 through a tube 12. The end of the bellows is provided with a micro-switch 12" connected to the closed vessel. The bellows actuates the switch by the vapor pressure in chamber 3 and switches on and off a connection between a power source 13 and the heater 6. Due to the pressure variation, said bellows extends or contracts whereby said micro-switch controls current to the heater 6 whereby liquid in the closed vessel is automatically maintained at a predetermined temperature.

The housing of the heating apparatus is designated by the numeral 14. A heat insulating material 15 is disposed between the housing and the vessel. A cover 16 is opened or closed for inserting yarn into the channel 2. Heat insulating material 17 forms an inner layer of the cover 16. The separating vessel 9 is disposed directly adjacent the inner wall of case 14 without any heat insulating material, thus providing cooling surface for vapor coming through upper tube 8 into the separating vessel 9.

When heater 6 is energized to liquid 7, vapor is produced from the surface of the liquid and chamber 3 is filled with saturated vapor.

A length of crimped yarn passing through the channel 2 is heat set by the heat delivered through the wall of vessel. Saturated vapor condsensing on the inner wall of the vessel 1 drains back into liquid 7 and is again heated and again evaporated. When this cycle of evaporation and condensation is repeated for a long time, vapor containing the low boiling point phase, which is unavoidably involved in heat medium liquids tends to delay its condensation relative to other materials present. Such low boiling point vapor will tend to localize it in the upper part of the closed vessel 1. If such low boiling point vapor is permitted to thus localize the temperature in the upper part of the closed vessel 1 will become lower than that of the bottom part.

The apparatus of the present invention is provided with the tube 8 in the upper part of the vessel, whereby such low boiling point vapor enters into the separating vessel 9.

Since portions of the walls of this separating vessel are not heat insulated, vapor therein is cooled by these portions and such low boiling point vapor is condensed and falls to the bottom of chamber 9'.

Thus accumulated liquid enters to the other chamber 9" through the space 10" beneath the lower end of balfie 10.

When the liquid level rises higher than the top of the standpipe 11, it overflows thereinto. However it takes some time before liquid overflows into said return pipe 11.

Liquid therein consists of the condensed liquid from the pure phase of the heat medium liquid vapor and that from the low boiling point vapor phase. Generally the specific garvity of low boiling point phase (water) is less than that of the pure phase. Therefore, in the separating vessel, the low boiling point phase will float on the pure phase as upper and lower layers, respectively. Therefore the liquid passing through the space 10 beneath the lower end of battle 10 into the other chamber 9" is substantially of the pure phase.

Thus liquid in this vessel gradually increases and when its level rises higher than the opening at the end of pipe 11, the pure phase liquid therein returns through the pipe 11 into the lower communicating tube and then into the bottom of closed vessel 1 where it is again heated and recycled.

As the operation continues, the heat medium liquid in vessel 1 becomes more purified resulting in the temperature all along the length of the vessel being maintained at a uniform temperature because of the absence of low boiling point vapor more and more in the upper part of vessel 1.

Also as the separating vessel 9 is naturally cooled, the pressure therein is somewhat lowered. As a result vapor from the closed vessel 1 flows more freely in the upward direction ,whereby the temperature along the length of the vessel is more uniformly maintained. Even when the vessel is to be utilized with a lower temperature, the temperature distribution will be maintained evenly. Thus, temperature range is greatly widened.

A second embodiment is shown in FIGS. 4 and 5 wherein a closed vessel 21, like vessel 1 of the first embodiment, is pipe-shaped and both ends are closed. The side 22, like side 2 of the first embodiment, thereof is grooved to provide a yarn passing channel. A vapor chamber 23, heat insulating material 2, a lower communicating tube 25, a heater 26, a heat medium liquid 27, an upper communicating tube 28, a separating vessel 29, a bafile 30, a standpipe 31, bellows 32, a housing 34 and heat insulating material 35 correspond to members 3 to 15, respectively, of the first embodiment.

The differences between the first and second embodiments are such that in the latter, a separating vessel 29 is housed in a heat exchanger and a vapor or air outlet 41 in this heat exchanger 40 is communicated to the vapor or air port 42 at the bottom of closed vessel 21 through a tube 43 extending downwardly and a header 43'. Also, vapor or air inlet 44 of heat exchanger 40 is communicated to vapor or air suction port 45 in the upper part of the vessel 21 through upper vapor or air tube 46 and upper header 46'. Channel 22 is covered by a cover 47.

Vapor or air is let into heat exchanger 40 from vapor or air inlet 44 which vapor or air is heated by the heat medium vapor in separating vessel 29. Thus, the temperature of such vapor or air is raised while the temperature of the heat medium vapor itself is lowered sufliciently to be condensed.

The condensed heat medium will circulate as in the first embodiment. On the other hand, vapor or air thus heated flows down through a lower vapor tube 43 and header 43' to vapor discharge port 42 adjacent the bottom of the closed vessel 21. Therefrom a high temperature vapor is jetted into channel 22 and further flows upward whereby a length of yarn therein is vapor heated.

Oily vapor attached to the surface of yarn flows up together with other vapors and is introduced into the vapor suction inlet 45. Thence, it flows through upper vapor tube 46 and upper header 46' and is vented from the apparatus.

Either vapor or air may enter the inlet 44 to the heat exchanger 40. Using vapor, for example, it is heated in the heat exchanger 40 with the heat delivered from heat medium vapor in the separating vessel. Yarn is heated with this heated vapor with nearly no heat loss. Thus very good thermal efficiency is effected.

FIG. 7 shows a third embodiment wherein a closed vessel is pipe-shaped. A channel 52 is provided in the center to pass yarn therethrough. This is the only variation from the second embodiment.

From the foregoing, it will be apparent that the apparatus for heat setting synthetic fibre yarns of this invention automatically eliminates unfavorable caused by a low boiling point material, which is inevitably included in a heat medium liquid and to operate with high thermal efiiciency.

The three described embodiments of this invention are disclosed specifically with reference to the drawings. However it is to be understood that the invention is not limited to these embodiments but any change or modification in the construction may be made within the scope of the appended claims without departing from the spirit of this invention.

We claim:

1. Apparatus for heat setting synthetic fibre yarns which comprises a plurality of vertical type of closed vessels, each of the vessels having a predetermined number of narrow channels for letting yarn pass therethrough, said vessels being connected and communicated to one another by lower tubes, a separating vessel provided with a partition therein positioned to leave a space beneath the lower end of the partition and divide the separating vessel into two chambers, a heater immersed in a heat medium liquid filled in the bottom part of the vessels, upper communicating tubes extending from said vessels to said separating vessel and a return tube communicating from said separating vessel to the lower part of each of said closed vessels.

2. The apparatus of claim 1 further characterized by: the upper communicating tubes open to one of the chambers partitioned by a partition plate in said separating vessel and the return tube is open to the other chamber in said separating vessel.

3. The apparatus of claim 1 further characterized by: in said separating vessel, the top end of said return tube is positioned at a higher level than the lowest end of said partition.

4. The apparatus of claim 1 further characterized by: each closed vessel is surrounded by heat insulating material and a cooling section is provided around the separating vessel.

5. Apparatus for heat setting synthetic fibre yarns as claimed in claim 1 comprising a heat exchanger housing said separating vessel, an upper vapor pipe communicating from a vapor suction inlet in the upper part of said closed vessel to the vapor inlet of said heat exchanger, lower vapor tubes leading from a vapor outlet in said heat exchanger to a vapor jet port in the lower part of said closed vessel.

6. Apparatus of claim 5 further characterized by: the vertical type of a closed vessel is constructed with a plurality of pipes.

7. Apparatus of claim 6 further characterized by; the narrow channel to pass yarn through is housed in the vertical vessel.

References Cited UNITED STATES PATENTS 2/1959 Kinney. 1/1967 Kodaira 28-62 X 

